Lab Report 2- Head Loss in Pipe & Bends

8/9/2019 Lab Report 2- Head Loss in Pipe & Bends

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EM201 FLUID MECHANICS

LABORATORY REPORT

EXPERIMENT 2

HEAD LOSS IN PIPE & BENDS

Name: GAN KIN LEONG

ID: 10012320

C!"#$e: BE%' Pe(#!)e"m E%*%ee#*%

FACULTY OF ENGINEERING

FACULTY OF ENGINEERING+ ARCHITECTURE AND

BUILT EN,IRONMENT

SEPT 2-+ 2013

TABLE OF CONTENT

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CONTENTS PAGE NO'

1. Introduction

a. Objective 3

b. Learning Outcomes 3

c. Introduction 3-6

2. Material and Methodology

a. Aaratus 6

b. !recautions "

c. !rocedure #!art 1 $ 2% "-& $ 1'

3. (esults and )iscussions

a. (esults $ *alculations #!art 1 $ 2% &-12 $ 1'-1"

b. )iscussions #!art 1 $ 2% 13 $ 1&

'. *onclusion 1&

+. (e,erence 1

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OB.ECTI,E

1. o determine the head loss in ie ,lo/ ,or di,,erent ie diameter.

2. o estimate the ,riction ,actor ,or di,,erent ie diameter.

3. o determine the head losses in bends.

'. o identi,y the tyes o, ,lo/ o, the ,luid.

LEARNING OUTCOME

0on comletion o, the eeriment students should be able to determine the head loss in ie

,lo/ ,or di,,erent ie diameter. In addition students are able to lot the grah o, ,riction ,actor

against (eynolds number. tudents should also be able to determine the head losses in each bend

and ,ind the ressure dro along the ie. 4urthermore they should be able to lot the grah o,

5 against 7282g to obtain 9 ,or all the ,our bends.

INTRODUCTION

I, you /ant to move something there /ill be resistance. I, you try to ush a heavy bo along the

ground it /ill re:uire a certain amount o, e,,ort to do it. ince the /eight and the si;e o, the bo

/ill not change the /or< re:uired should be the same regardless o, the sur,ace it is resting

on. o/ever the bo /ill be much easier to move on a smooth linoleum ,loor than trying to

move it on a dee ile caret. he di,,erence in the re:uired e,,ort is due to ,riction. he caret

has a higher resistance to the movement o, the bo than the smooth ,loor.

o move a given volume o, li:uid through a ie re:uires a certain amount o, energy. An energy

or ressure di,,erence must eist to cause the li:uid to move. A ortion o, that energy is lost to

the resistance to ,lo/. his resistance to ,lo/ is called head loss due to ,riction.

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In ,luid dynamics head is a concet that relates the energy in an incomressible ,luid to the

height o, an e:uivalent static column o, that ,luid. 4rom =ernoulli>s !rincile the total energy at

a given oint in a ,luid is the energy associated /ith the movement o, the ,luid lus energy ,rom

ressure in the ,luid lus energy ,rom the height o, the ,luid relative to an arbitrary datum. ead

is eressed in units o, height such as meters or ,eet.

ead loss is the measure o, the reduction in the total head o, the li:uid as it moves through a

system. he total head is the sum o, the elevation head velocity head and ressure head. ead

loss is unavoidable and is resent because o, the ,riction bet/een the ,luid and the /alls o, the

ie and is also resent bet/een adjacent ,luid articles as they ,lo/ along the ie. ead loss is

a measure o, the reduction in the total head #sum o, elevation head velocity head and ressure

head% o, the ,luid as it moves through a ,luid system. his is unavoidable in real ,luids.

'

http://en.wikipedia.org/wiki/Fluid_dynamicshttp://en.wikipedia.org/wiki/Bernoulli's_Principlehttp://en.wikipedia.org/wiki/Datum_(geodesy)http://en.wikipedia.org/wiki/Datum_(geodesy)http://en.wikipedia.org/wiki/Bernoulli's_Principlehttp://en.wikipedia.org/wiki/Datum_(geodesy)http://en.wikipedia.org/wiki/Fluid_dynamics


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ead loss is the combination o, di,,erent tyes o, losses.

1- 4riction loss occurs as the ,luid ,lo/s through the straight ies.

2- Minor losses are head losses that occur due to bends elbo/s joints valves and other ,ittings

in the systems.

?henever there is a change in the direction o, ,lo/ or a change in the cross-sectional area a head

loss /ill occur.

4riction losses are very deendent uon the viscosity o, the li:uid and the amount o,

turbulence in the ,lo/. ead loss due to ,riction can be calculated by using the )arcy-?eisbach

e:uation. )arcy>s e:uation can be used to calculate ,rictional losses. A secial ,orm o, this

e:uation can be used to calculate minor losses. 4riction loss is that art o, the total head loss that

occurs as the ,luid ,lo/s through straight ies. he head loss ,or ,luid ,lo/ is directly

roortional to the length o, ie the s:uare o, the ,luid velocity and a term ,or ,luid ,riction

called the ,riction ,actor. he head loss is inversely roortional to the diameter o, the ie.

?hen calculating heat trans,er or ressure and head loss it is imortant to t moving at all.

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ransitional ,lo/

ransitional ,lo/ is a miture o, laminar and turbulent ,lo/ /ith turbulence in the center o, the

ie and laminar ,lo/ near the edges. @ach o, these ,lo/s behave in di,,erent manners in terms

o, their ,rictional energy loss /hile ,lo/ing and have di,,erent e:uations that redict their

behavior.

urbulent ,lo/

In turbulent ,lo/ vortices eddies and /a


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APPARATUS

!ie 4riction Aaratus he ydraulics =ench its various accessories and the associated

eerimental e:uiment as /ell as a sto/atch.

PRECAUTIONS

1. he manometer tube is ensured to be ,ree ,rom air bubbles and that readings are ta


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1. he L-1&DD1-1+ !ie 4riction Aaratus /as laced on the hydraulic bench.

2. he /ater inlet and outlet niles are connected /ith ,leible hose.

3. he :uic< couling is connected to the coer /ire o, 11mm inner diameter.

'. he /ater um is s/itched on and the hydraulic bench is closed over ,lo/ slo/ly.

+. he valves at the coer ie are oened and the air ga in the manometer are removed by ressing the relie, valve /hich is located at the to o, the manometer. he ,lo/ rate is measured

by a measuring bea


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i% 11 mm

ii% &.3 mm

iii% +.3 mm

1D


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DISCUSSIONS /Pa#( 1

According to the results obtained it can be said that the head loss gets larger /hen the cross-

sectional area o, the ie decreases. he +.3mm ie sho/ed the largest head loss value.

4rom the calculations the velocity and (eynolds number ,or 11mm ie is the lo/est among all

the three #3% di,,erent si;es o, the ies sho/ing values o, less than 'DDDD /hich are sho/n in

the grah o, ,riction ,actor against (eynolds number as lotted above. here,ore /ith less than

2'DD o, (eynolds number the ,luid ,lo/ing through the 11mm ie /ould be laminar ,lo/

/here the ,luid /ill move in a straight ath. ?hereas ,or the &.3mm ie the (eynolds number

is in bet/een laminar ,lo/ and turbulent ,lo/ /ith 26DD and 'DDD /hich is transitional ,lo/. In

this ,lo/ the ,luid /ill ,lo/ in a medium velocity. As ,or the +.3mm ie /ith the highest

(eynolds number calculated o, more than 'DDD the ,luid /ill ,lo/ in a turbulent ,lo/ /ith high

velocity. 4rom the grah it can deduced that the ,riction ,actor is high /hen the total head loss is

high and lo/ /hen the total head loss is lo/.

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PART 2: HEAD LOSS IN A BEND

PROCEDURE /Pa#( 2

1. he inlet valve is connected to the hydraulic bench suly.

2. he inlet and outlet valve are ,ully oened and /ater ,lo/ rate is controlled ,rom the

hydraulic bench.3. he ,lo/ rate o, /ater is measured by a measuring bea


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reynoldsnumber=0.937 x 0.0167

9.04 x 10−7 =17310

friction factor=−0.0016ln ( x )+0.0028

friction factor=−0.0016ln (17310 )+0.0028=7.19 x 10−3

losscoefficient , K =∆ h

v2

2g

loss coefficient , K = 0.0386

0.9372

2 (9.81 )

=0.86

4or ,lo/ rate o, D.2D+3 L8s

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4or ,lo/ rate o, D.2D+3 L8s

4or ,lo/ rate o, D.1"3& L8s

4or ,lo/ rate o, D.1D'" L8s

4or ,lo/ rate o, D.D6 L8s

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DISCUSSIONS /Pa#( 2

4rom the results obtained it can be sho/n that values o, the reading ,rom tube 1 to tube 1D

decreases. he readings recorded on the manometer decrease as the ,lo/ rate and velocity are

lo/ered. As sho/n in the manometer tubes 1 $ 2 3 $ ' and " $ & as /ell as $ 1D are used to

measure the head losses ,or the ies /ith D degrees large radius bend D degrees small radius

bend D degrees small elbo/ bend and t/o #2% '+ degrees bends resectively /hile readings

,rom tubes + $ 6 are used to measure the sudden contraction and enlargement in large diameters.

=ased on the calculations in !art 2 the total head loss is highest /ith the volumetric ,lo/ rate.

Analy;ing the grah lotted /e can see that the head loss in '+ degrees bend is higher than the

D degrees bend /hereas the head loss in sudden contraction in the ie diameter is higher than

,or sudden enlargement in ie.

CONCLUSION

he objectives o, the eeriment have been achieved. In conclusion ,or !art 1 the eeriment

allo/ed us to determine the head losses in the di,,erent cros-sectional areas o, the ies. =y

calculating the (eynolds number and lotting the values /ith ,riction ,actor /e /ere able to

identi,y the tyes o, ,lo/ o, the ,luid /hether the ,luid is laminar ,lo/ transitional ,lo/ or

turbulent ,lo/.

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In conclusion ,or !art 2 the eeriment allo/ed us to identi,y the head losses in di,,erent tyes

o, ie bends and the ressure dro along the ies ranging ,rom di,,erent angles o, bending and

sudden contraction and enlargement. *alculating the results recorded to obtain value o, total

head losses the values are lotted in a grah to obtain loss coe,,icient 9.

REFERENCES

1. Merie !otter #2DD"%. Schaum’s Outline of Fluid Mechanics. McEra/-ill

2. httB88///.engineeringtoolbo.com8reynolds-number-dF23".html

3. httB88///.hydromatic.com8(esidential!ageFtechin,oageFheadloss.as

2D
http://www.engineeringtoolbox.com/reynolds-number-d_237.htmlhttp://www.hydromatic.com/ResidentialPage_techinfopage_headloss.aspxhttp://www.engineeringtoolbox.com/reynolds-number-d_237.htmlhttp://www.hydromatic.com/ResidentialPage_techinfopage_headloss.aspx

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Lab Report 2- Head Loss in Pipe & Bends